1. Field of the Invention
This invention relates to computer systems that can use one of two optional CPUs. More particularly, it relates to computer systems that have optional CPUs and an automatic detection circuit for detecting which type of optional CPU is employed.
2. Description of the Prior Art
A typical prior art solution was to add a pin to the chip implementing the CPU to indicate the type of CPU.
A more advanced prior art technique is that used when the CPU and a co-processor, for example, which are normally bilaterally connected, have the pin(s) ordinarily used for such communication to indicate the presence or absence of the co-processor at start-up.